5-(4'-Methoxybenzoyl)-indan-2,2-dicarboxylic acid → 5-(4'-Methoxybenzoyl)-indan-2-carboxylic acid

Participants

Reaction Steps

77.5 g (0.228 mole) of the crude acid obtained in (d) and 1070 cm3 of concentrated hydrochloric acid are placeed in a 2 liter reaction vessel equipped with a stirrer and cooler. The mixture is heated to reflux for 15 hours. After cooling, the reaction mixture is extracted with diethyl ether, the extract dried over anhydrous sodium sulphate, filtered, and the filtrate concentrated. A doughy solid is obtained which, after recrystallization from ethyl acetate, melts at 149°-151° C. (capillary tube). If difficulty is experienced in purifying the acid by recrystallization, the methyl ester of the acid may first be formed, for example, and purified by distillation (boiling point at 0.67 torr=218° C.) and then hydrolyzed with aqueous alcoholic potash using a known method. The acid obtained is thus more easily able to be purified.

Provenance & Evidence